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-rw-r--r--python/trx/radio_if.py268
1 files changed, 249 insertions, 19 deletions
diff --git a/python/trx/radio_if.py b/python/trx/radio_if.py
index 9e97277..355312b 100644
--- a/python/trx/radio_if.py
+++ b/python/trx/radio_if.py
@@ -2,7 +2,7 @@
# -*- coding: utf-8 -*-
# GR-GSM based transceiver
-# Extending a GRC flowgraph gr-gsm/examples/trx_radio_if/radio_if_grc.grc
+# Follow graph implementation
#
# (C) 2016-2017 by Vadim Yanitskiy <axilirator@gmail.com>
# (C) 2017 by Piotr Krysik <ptrkrysik@gmail.com>
@@ -23,37 +23,267 @@
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-from grgsm.trx import radio_if_grc
+import pmt
+import time
+import grgsm
+import osmosdr
+
+from math import pi
+
+from gnuradio import digital
+from gnuradio import blocks
+from gnuradio import uhd
+from gnuradio import gr
+
+from gnuradio import filter
+from gnuradio.filter import firdes
+
+
+# HACK: should be implemented in C++!
+class dict_toggle_sign(gr.basic_block):
+ def __init__(self): # only default arguments here
+ gr.basic_block.__init__(self,
+ name='Change sign of elts in dict',
+ in_sig=[],
+ out_sig=[]
+ )
+ self.message_port_register_in(pmt.intern("dict_in"))
+ self.message_port_register_out(pmt.intern("dict_out"))
+ self.set_msg_handler(pmt.intern("dict_in"), self.change_sign)
+
+ def change_sign(self, msg):
+ if pmt.is_dict(msg):
+ d = pmt.to_python(msg)
+ for key, value in d.items():
+ d[key] *= -1
+ self.message_port_pub(pmt.intern("dict_out"), pmt.to_pmt(d))
+
+class radio_if(gr.top_block):
+ # PHY specific variables
+ rx_freq = 935e6
+ tx_freq = 890e6
+ osr = 4
-class radio_if(radio_if_grc):
# Application state flags
trx_started = False
+ # GSM timings (in microseconds [uS])
+ # One timeslot duration is 576.9 μs = 15/26 ms,
+ # or 156.25 symbol periods (a symbol period is 48/13 μs)
+ GSM_SYM_PERIOD_uS = 48.0 / 13.0
+ GSM_TS_PERIOD_uS = GSM_SYM_PERIOD_uS * 156.25
+ GSM_UL_DL_SHIFT_uS = -(GSM_TS_PERIOD_uS * 3)
+
+ # FIXME: shall be measured (automatically?) for
+ # particular device and particular clock rate.
+ # The current value is measured for USRP B2X0 at 26e6.
+ delay_correction = (285.616 + 2 * GSM_SYM_PERIOD_uS) * 1e-6
+
def __init__(self, phy_args, phy_sample_rate,
phy_rx_gain, phy_tx_gain, phy_ppm,
phy_rx_antenna, phy_tx_antenna,
- trx_remote_addr, trx_base_port,
- phy_tx_freq=938900000,
- phy_rx_freq=938900000-45e6,
- delay_correction=285.616e-6,
- uplink_shift=-(6.0/1625000*(156.25)*3),
- timing_advance=0):
+ trx_remote_addr, trx_base_port):
print("[i] Init Radio interface")
- radio_if_grc.__init__(self,
- samp_rate=phy_sample_rate,
- tx_gain=phy_tx_gain, rx_gain=phy_rx_gain,
- tx_freq=phy_tx_freq, rx_freq=phy_rx_freq,
- osr=4, ppm=phy_ppm,
- trx_base_port=str(trx_base_port),
- trx_remote_addr=trx_remote_addr,
- delay_correction=delay_correction,
- uplink_shift=uplink_shift,
- timing_advance=timing_advance)
+ # PHY specific variables
+ self.sample_rate = phy_sample_rate
+ self.rx_gain = phy_rx_gain
+ self.tx_gain = phy_tx_gain
+ self.ppm = phy_ppm
+
+ gr.top_block.__init__(self, "GR-GSM TRX")
+
+ # TRX Burst Interface
+ self.trx_burst_if = grgsm.trx_burst_if(
+ trx_remote_addr, str(trx_base_port))
+
+
+ # RX path definition
+ self.phy_src = uhd.usrp_source(phy_args,
+ uhd.stream_args(cpu_format="fc32",
+ channels=range(1)))
+
+ self.phy_src.set_clock_rate(26e6, uhd.ALL_MBOARDS)
+ self.phy_src.set_center_freq(self.rx_freq, 0)
+ self.phy_src.set_antenna(phy_rx_antenna, 0)
+ self.phy_src.set_samp_rate(phy_sample_rate)
+ self.phy_src.set_bandwidth(650e3, 0)
+ self.phy_src.set_gain(phy_rx_gain)
+
+ self.msg_to_tag_src = grgsm.msg_to_tag()
+
+ self.rotator_src = grgsm.controlled_rotator_cc(
+ self.calc_phase_inc(self.rx_freq))
+
+ self.lpf = filter.fir_filter_ccf(1, firdes.low_pass(
+ 1, phy_sample_rate, 125e3, 5e3, firdes.WIN_HAMMING, 6.76))
+
+ self.gsm_receiver = grgsm.receiver(self.osr, ([0]), ([]))
+
+ self.ts_filter = grgsm.burst_timeslot_filter(0)
+ self.ts_filter.set_policy(grgsm.FILTER_POLICY_DROP_ALL)
+
+ # Connections
+ self.connect(
+ (self.phy_src, 0),
+ (self.msg_to_tag_src, 0))
+
+ self.connect(
+ (self.msg_to_tag_src, 0),
+ (self.rotator_src, 0))
+
+ self.connect(
+ (self.rotator_src, 0),
+ (self.lpf, 0))
+
+ self.connect(
+ (self.lpf, 0),
+ (self.gsm_receiver, 0))
+
+ self.msg_connect(
+ (self.gsm_receiver, 'C0'),
+ (self.ts_filter, 'in'))
+
+ self.msg_connect(
+ (self.ts_filter, 'out'),
+ (self.trx_burst_if, 'bursts'))
+
+
+ # TX Path Definition
+ self.phy_sink = uhd.usrp_sink(phy_args,
+ uhd.stream_args(cpu_format="fc32",
+ channels=range(1)), "packet_len")
+
+ self.phy_sink.set_clock_rate(26e6, uhd.ALL_MBOARDS)
+ self.phy_sink.set_antenna(phy_tx_antenna, 0)
+ self.phy_sink.set_samp_rate(phy_sample_rate)
+ self.phy_sink.set_center_freq(self.tx_freq, 0)
+ self.phy_sink.set_gain(self.tx_gain)
+
+ self.tx_time_setter = grgsm.txtime_setter(
+ 0xffffffff, 0, 0, 0, 0, 0,
+ self.delay_correction + self.GSM_UL_DL_SHIFT_uS * 1e-6)
+
+ self.tx_burst_proc = grgsm.preprocess_tx_burst()
+
+ self.pdu_to_tagged_stream = blocks.pdu_to_tagged_stream(
+ blocks.byte_t, 'packet_len')
+
+ self.gmsk_mod = grgsm.gsm_gmsk_mod(
+ BT = 0.3, pulse_duration = 4, sps = self.osr)
+
+ self.burst_shaper = digital.burst_shaper_cc(
+ (firdes.window(firdes.WIN_HANN, 16, 0)),
+ 0, 20, False, "packet_len")
+
+ self.msg_to_tag_sink = grgsm.msg_to_tag()
+
+ self.rotator_sink = grgsm.controlled_rotator_cc(
+ -self.calc_phase_inc(self.tx_freq))
+
+ # Connections
+ self.msg_connect(
+ (self.trx_burst_if, 'bursts'),
+ (self.tx_time_setter, 'bursts_in'))
+
+ self.msg_connect(
+ (self.tx_time_setter, 'bursts_out'),
+ (self.tx_burst_proc, 'bursts_in'))
+
+ self.msg_connect(
+ (self.tx_burst_proc, 'bursts_out'),
+ (self.pdu_to_tagged_stream, 'pdus'))
+
+ self.connect(
+ (self.pdu_to_tagged_stream, 0),
+ (self.gmsk_mod, 0))
+
+ self.connect(
+ (self.gmsk_mod, 0),
+ (self.burst_shaper, 0))
+
+ self.connect(
+ (self.burst_shaper, 0),
+ (self.msg_to_tag_sink, 0))
+
+ self.connect(
+ (self.msg_to_tag_sink, 0),
+ (self.rotator_sink, 0))
+
+ self.connect(
+ (self.rotator_sink, 0),
+ (self.phy_sink, 0))
+
+
+ # RX & TX synchronization
+ self.bt_filter = grgsm.burst_type_filter([3])
+ self.burst_to_fn_time = grgsm.burst_to_fn_time()
+
+ # Connections
+ self.msg_connect(
+ (self.gsm_receiver, 'C0'),
+ (self.bt_filter, 'bursts_in'))
+
+ self.msg_connect(
+ (self.bt_filter, 'bursts_out'),
+ (self.burst_to_fn_time, 'bursts_in'))
+
+ self.msg_connect(
+ (self.burst_to_fn_time, 'fn_time_out'),
+ (self.tx_time_setter, 'fn_time'))
+
+
+ # AFC (Automatic Frequency Correction)
+ self.gsm_clck_ctrl = grgsm.clock_offset_control(
+ self.rx_freq, phy_sample_rate, osr = self.osr)
+
+ self.dict_toggle_sign = dict_toggle_sign()
+
+ # Connections
+ self.msg_connect(
+ (self.gsm_receiver, 'measurements'),
+ (self.gsm_clck_ctrl, 'measurements'))
+
+ self.msg_connect(
+ (self.gsm_clck_ctrl, 'ctrl'),
+ (self.msg_to_tag_src, 'msg'))
+
+ self.msg_connect(
+ (self.gsm_clck_ctrl, 'ctrl'),
+ (self.dict_toggle_sign, 'dict_in'))
+
+ self.msg_connect(
+ (self.dict_toggle_sign, 'dict_out'),
+ (self.msg_to_tag_sink, 'msg'))
def shutdown(self):
print("[i] Shutdown Radio interface")
self.stop()
self.wait()
+ def calc_phase_inc(self, fc):
+ return self.ppm / 1.0e6 * 2 * pi * fc / self.sample_rate
+
+ def set_rx_freq(self, fc):
+ self.phy_src.set_center_freq(fc, 0)
+ self.rotator_src.set_phase_inc(self.calc_phase_inc(fc))
+ self.rx_freq = fc
+
+ def set_tx_freq(self, fc):
+ self.phy_sink.set_center_freq(fc, 0)
+ self.rotator_sink.set_phase_inc(-self.calc_phase_inc(fc))
+ self.tx_freq = fc
+
+ def set_rx_gain(self, gain):
+ self.phy_src.set_gain(gain, 0)
+ self.rx_gain = gain
+
+ def set_tx_gain(self, gain):
+ self.phy_sink.set_gain(gain, 0)
+ self.tx_gain = gain
+
+ def set_ta(self, ta):
+ print("[i] Setting TA value %d" % ta)
+ advance_time_sec = ta * self.GSM_SYM_PERIOD_uS * 1e-6
+ self.tx_time_setter.set_timing_advance(advance_time_sec)